The present invention relates to devices for delivering, administering, dispensing, injecting and infusing substances, and to methods of making and using such devices. More particularly, the present invention relates to a catheter head for medical, therapeutic and pharmaceutical applications or uses. In some embodiments, the catheter head can be part of an infusion set or can form an infusion set together with a catheter and/or one or more other elements conveying fluid. In some embodiments, the present invention may be used for the subcutaneous administration of a liquid medicament, for example insulin, and, in some embodiments, it may be used for self-administration.
Catheter heads that form part of an infusion set are known from the prior art. For example, EP 0 239 244 B1 discloses an injection set for subcutaneous injection. The core part of the injection set is a catheter head. This catheter head comprises a delivery line for the product to be injected, a flexible cannula protruding or extending from the catheter head, and a puncture needle attachment. To deliver or inject fluid into a patient, a puncture needle is guided through the puncture needle attachment into the catheter head and through the flexible cannula to insert the latter into the patient's tissue. The puncture needle pierces a septum on the puncture needle attachment. After the flexible cannula has been inserted into the patient's tissue by means of the puncture needle, the puncture needle is withdrawn from the catheter head. In this process, the septum on the puncture needle attachment seals the catheter head. A tight connection is thus established between the cannula in the tissue and a delivery means for the product. However, because of the septum on the puncture needle attachment being pierced, there is a danger of the connection not providing a complete seal. This applies especially when the septum on the puncture needle attachment is pierced several times.